SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c3bf0dcc748177c08c1d40bb810daafda41a94405a55bb6ac55e7722e273eb9' 
  AND token = 'ysesgz4qH4Ad8C6mXVy62cJOgBQlZkSCBhc2r1d1bTk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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