SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2d60e1e177e10e68dbfd8d8ff7e2c5382af616979354bb1e2dfe6815583d68e' 
  AND token = '8+QYTZqz1rARU5MmYh/kX7mViiQgHtYFxs5Ric3xv1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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