SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0f100ca6afe85a1bbb2468c0161091d3ff046fa4feadd249c9cde700e4f7da3' 
  AND token = 'quTOkCPXI1mnaysDy4SmHdBdCDKNS8RANDEVi2m357M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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