SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0eb53ab1b9ff418c35f32770b372a252df802b36c92335e0ed792c722f8baade' 
  AND token = 'N6WRcrwihuPMUnQoNnBE0THpdfgNqZHgIHFMCuBVDQ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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