SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b5d655959f3dc9a7602cca352c062c35af91f3fefba521c61ea2265786136c57' 
  AND token = 'er3LkZ4TfHTcjsGAFLynzMQApPyVRV2brFnN7EqzVJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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