SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7dd09421587932521ee61004376ca1a2ce47aa53ec62ab9db9987b571c5fc0b' 
  AND token = 'BhwsEFxiiIWsqEOc1Tp9i8rDBMiFJHQrrh0Vu2BeOgg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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