SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b383a30c52044907905df13067eedbce4f92caa1c334e27fca0897b29172be2' 
  AND token = 'FoEDnQPpZEl01CCPsK06kQvECJh+HGQjEqGVTDWGe2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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