SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '094a8455ae8e7400c53284cdc5f71129ee2e322200b289cdb318c2044f36a420' 
  AND token = 'KYbrnUEBo6yk6WFtiI3fsV91KAZ/ulvtEYD1rdFhkRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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