SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ecd5c5b33a979404cb4054a309d5f9d81af61a7b8a8543efe3c1179287b0ff12' 
  AND token = 'z5L9kt3sYc8Fa+chGBdBNN95AQpSlp8hYrQ6OTE0J2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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