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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33be83e5b152973fb0f5f9bfaab910a904b4f2ac9c9b7f7bd2a9cc1cfa50b25b' 
  AND token = 'UQQNx8QDSt2ozTo/Saf4Q8Gb+XOd3Ilzyntg3GOpFMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}