SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8382bbd604d7a60a8b783aab386ccaa103aa3d994c12802635d670df2b9045e2' 
  AND token = '1fl6UlyErkNCTvhA43vSJYdEOaYXvPhfLb3x0JJtQ7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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