SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30f47cef6926b6439a90f3e941eef9a8c37efd05116dd3e4c735ce88aff65dc8' 
  AND token = 'FgVqe2LJTRJWQ6JcnWT+9pLwy+oAm1hgar5EYz2p7/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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