SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '04b2d259a1f1f222c02ad5296c6f343b437a4a4fd0590951404ec5b0efb331eb' 
  AND token = 'hDIsyGdIqvDF+t0PFON69osI+IEwaT0fEscdEa4IcQg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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