SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9214eb7299baadead135d16e36f43730961ea9671f3366ff3074148f35ec27c3' 
  AND token = 'pGNcGLb98OACUZzEcVHGqtvbUljkraaumByASwI+Nhk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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