SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0396e813ada700ce2f559f6abfb01d8c157b3c617cc3db1f016261750230c51' 
  AND token = 'qhBB7qsdIZiVbyuqfHFp6UG7eWQjA19+Zq+HNAD2CGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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