SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bb68ec5a106da7a43b024e917219da398a44d2518df1dd3c9abf554097d93e7' 
  AND token = 'LhEqJitcFjTYDwiT2QhyJ6nyBQR+z+BCNZMAezne6+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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