SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1294a37ff769086763a786ead78f04e45dd946b10254259399f995a11b7c5b5f' 
  AND token = 'BA7mPyJfRLanIA5vWzxliuNl/TUdChmu5FqCqJJ6sXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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