SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d9ca10e7a3c48181ab60fa8caf776507e95b84001cb43d59b3b421222717152' 
  AND token = 'XsvWhtVV661FT3NGZnYw0efZlxlMVQaC+C6Yj2IY/Bk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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