SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '558fa24003031dd7da0a3fea7327d023a752b59061b434e3fd0b45c9be220e62' 
  AND token = '9TaIoB45My9oHmRCwjtjaUQXz60kTY7YWA3o1SmOuP4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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