SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91cfaee886f72cf0b48ed240ab51fc24ea5b883ef63be887c1e36c885bcdc933' 
  AND token = '1k40ZqLMYZbs8MrzsAawq50r8lnrXVU7+yBkkjiGv8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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