Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6bbc78953f9cf7cd86f2f0bd88931dcd8036e5f320e249cc1e01b31d6cc23e3' 
  AND token = 'L2Bjv6UAp2rK2f9XxZzWzgTpWzLyfbEj/46hqAJAIKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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