SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b25c9604598980649540f6aff7c54a50d26738e0e7171ecd4f5d733a94cbfdb1' 
  AND token = 'uZHKCAnlAqEMPdE0cVrz5ILl6y+jkej4SoZhw4iBRyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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