SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a554ddd19d9a575bb8a365dc0915187512f4babb5bf2d5309bc9cdc6cc5756ee' 
  AND token = 'NFAn2AF6hsJgiot3sHggkiCBRnrwb3jScPTTGRMm75A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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