SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7ea6ac86175b4d22f6ddf988f4768c46c1e6d659df9850b59a806e5c5f2af8b6' 
  AND token = 'UknmN875jrjrKKGu04nVX2w3TS3tnJNZe+15KbKhIqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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