SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dcf42e7df41f817e29fc38dd9adaf742f43db94527899bbefd3cdd0cef6b5ed' 
  AND token = 'UDVg3CxRWzkajEryA/IKMESC/WrKnZnIANu2rLNbUdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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