SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8532e21adfa683f9dcf302f23458d451bd9fce11563b37dbb666f2778e1b6415' 
  AND token = 'Cvz+LMdlnBPqOSeZxBusVeDgfD1MA2YL9Lk8/KB4bEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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