SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0e120afea525833aeddac7d02f0d97f25758580f224cebd1301f1bbfe8693d03' 
  AND token = 'MgngLxqsOVWFedKhXUcVbPjDphtJj8iSB7HOrvG5Zds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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