SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8bfe85056902027b666cdaf1cf8e06bfae21806d6cd1a28a17069307cfb2d91' 
  AND token = 'lOnb+0C1vjUoUEaolt+xM5IdatrNL9IbRn58EX41a7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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