SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e273266111ffddcd9dfe9e53c777072e4c51f895e36e1a21c7aca83429c7a167' 
  AND token = 'jgsGESx4vNbUMW0YypyQlJL35L3Sx7IK9iYU6dIDqo0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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