SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '224c29cd1a2d2fed46eaa00d01c56901243fd6ccc4194dba49f1027a288c1d71' 
  AND token = 'ehPiPjAjGGmsyf+TTvpZXFavwuUhXSL2KM+lzQbFm6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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