Sandbox

SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a81a4400599b0ce9870373f01f951003808dddf13fc34ccebd621e841d0816d4' 
  AND token = '2shGpTjq2veS/EcUTVb4ACnx18nhA3XUpclJFSvN2RA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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