SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1c047157b5221277779292af52e0abff1da772980c0b83cabb26ce77c489062' 
  AND token = 'MvpaokTMO5GYcXxvKUYpSRzABHJq6Jtfe2tOJ55Hy/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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