SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9bb50e710a686d835803eacd837ef6bede9f187993ccf522003b2bbeb13b129' 
  AND token = 'SWY1wZ0Pr+/+eyA9T1hLReSW0riMs6iAqbF/9+i9Whs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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