SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e9a8fd77756ee19dbe914c9d2541666cad6529ec1689968de8f060ae285d9f5' 
  AND token = 'XOo9ae6FARwTJtJf/Nnf5OpWGBGVKhhnpGvn9RDbIKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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