SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19085e39012cbd3f03291bda82594950588e6088f539ad76aaee609b59c6c9ae' 
  AND token = 'xjX6NCiVmHyZH8ZDHbQkG33gUK84n6VnD3R9e0B1Fss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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