SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8afafaa999571692d453381b0d8742eb5b162c7bd054aa996a8dabf8922d687' 
  AND token = '4kIKGpW00SFQ/FhkG4lze+GKhHdVuRSXl+AyXQEEabk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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