SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3a7fb930558697d14dd8ac22b8a9b6d014075f1525f3d41d7fc91417f6adcd1a' 
  AND token = 'H5jQ5AhOg0BP4kojMVIM6KXQ2ep0uWw5l+pbaYw2WDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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