SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b33ab2d95e8c15441aab357cd1eeb359d13ac495c0d3153832553241ceace853' 
  AND token = 'A2sPJYCDCQ4zOa+hopJpduFSdYT/Kc+NRzxAmjSi0mc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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