SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de5f447cae2fac6be7a02040e910b8c8c729199646af41d7b436a72b22ddf42d' 
  AND token = 'YnfhnJkF1CIZabB2PPEOwOCXIHsTcUZOcEXr7u0YNlo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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