SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bb6364ea4996c231fb046bb3e722e80fba0e1af055021f26a36aaf692513e71' 
  AND token = 'w5WLlfs2IZD47IKwOaW3+49A2FUQlkIz5Kkz3U/ENS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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