Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4ef66ab78fc31463aa068ff4c1e9983e73dcd0cf0714d481ed596e4be6ecbd3' 
  AND token = 'UR+esQswUYJhd5af0RsguZta+ASolh+aEKGPuFr1YqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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