SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df9dee32b387f118f07966b83cc9db67c47a9d270a9ebbef41f582ec8116b86c' 
  AND token = '8pMwfnbTgErOhf8V6papIA3YzjH1/0fCpurdHOWKCkk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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