SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1303632a82609353eefe53791367025587284c1a11a3b1796bb4b896b320b12' 
  AND token = 'XBtLZhQ2vCZlo/GK77Pss7HDhnAeRq/ledINQGA6USU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}