SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ec403aefcbe56b2716d11bd7c36f12aef070bbd510f7bff6c93dacba464b25b3' 
  AND token = 'ewdDOeZmqEHgUCRMorQtzdlTPrqaICnHMdbSbM706SU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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