SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd27fa3f4d950afee39c7356157945bc33a230e7c2e589882d78e0a8f8f72526a' 
  AND token = 'VF3DoFA2X1dkah4+BgVLdvmCZYCfrDumuDIrq/xdELs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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