SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '36ca2a8994746f5c4c340883e0228827efaac5c12496607fac13e33409c9dd0f' 
  AND token = 'P2q2jAdzmipOLpsFVXBZak7idPfDTSSoMwI31yUSDK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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