SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '980400c511df6186364239d553525386fe77efd830210d84a230ade24d59a0d7' 
  AND token = 'LVCNjyGQ9AJhMU23j57ldglAYed/LL0S/nn9UkOjwCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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