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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4db7dee04fd2b7dc1d7d947e1845e41e07d0102e2a8abfb4792c6b39f40a7b1f' 
  AND token = 'dfvfKCJ7xYlRmDLdM//7dE4ritww22Oy4uMQEGQORYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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