SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1262263e270c54a427fe29360a22801667ecd93e7a4878ffc7958fede3bab619' 
  AND token = 'C7GxOLZi29iv+o3GjvGOgR0ajItwYthmJudlvzszgGQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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