SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a66d71d95ba1235b4fe0b8385104435b2a9417a39c98fa5daf6846b58eb5a5e5' 
  AND token = 'BMnjDg9Y2Xj9fJxRUSFJu/qx+KM7/upsoUIcDtsZ6gQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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