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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ebae9c3951616ba10a1a92e3b256426bfdf1d7339891b84ce99b58854df9dca' 
  AND token = 'mGD+XzCIs35HUVrieLXudCyUMP/tHcgF7s4Do4m8lS0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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