SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5efec32c6f395671409884d271087bda1906ccba12803b452247bb8973529f44' 
  AND token = '71XFciKKwVe274Yx6RAxhmkxPSJN67sqk5W4Rf5pBAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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