SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a4f374ad33c1ba303a60232528b5b2bcfe230bb53e9d732632616bfdb6f1219' 
  AND token = 'J4owHgk3AeZKCgzOXz/SDXLV8QE+KStnH7reBLeVUwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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