SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e88476d1af8e758fe4e367657bef7ab972a7419a178e7cfac46567497816fc5b' 
  AND token = 'GvED23LjdwBBTBmRARW3WL1CYACj5SXVp7ugVKIHfYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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