SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dae6e8770c5ba72db701cb83674a312476d73c1378eee5aaf5fea3113f044d7' 
  AND token = 'UHiP1WOxBvbTWNz9pPDKLTZGQH1XjVUvmEnuqxZaPkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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