SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '90ca0c13f891a1b91aa043e84597af3715b308588ea2c612831816048d8e97e3' 
  AND token = '+D5mfqKXG9/mc+hjc2YxwP4bNp697Q92+nHS3vrbtmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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