SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c305070ad916f375a547a51b7f576f6a2c8832e6baa2769a263084530dbc61c9' 
  AND token = 'xCWk0mJBoOvIVtATQSELGeQmIXRLUxTKXDmoZni8k1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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