SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eede2754bcbf8d3d4daf9a74121fb760f43fab7fd07c24d9d8942245821fa6b5' 
  AND token = 'mUp5ktEUtWUzMNMOi4i6yu84Dakqt+40CYD36BpLsDc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}