SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac5237f3d82ff2891ba38fc9b1f55ec50fc959e616d4dcc2dc8b2d3adae97a1a' 
  AND token = '2Mi2l3mGE9+YsPvgIlxHQsagBLbcxGj4Tc8Ai3Ieycs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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