SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90af7150dec6a3c1624d1e26da266dbddea3cafa34f1154793195073a963acc3' 
  AND token = '1hGrUzOBSCEb8+SyPJV+IFwIs2o00ivFUe9929tY6GA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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